低温生产高活性右旋糖苷蔗糖酶的明串珠菌的筛选

Selection of psychrotrophic Leuconostocs producing highly active dextransucrase

明串珠菌是异型发酵乳酸菌的一种,主要作用于蔬菜发酵食品的发酵初期,能够代谢生成CO2和多种风味化合物,是占有重要地位的发酵剂菌种之一。明串珠菌在蔗糖诱导下分泌右旋糖酐蔗糖酶,此酶分解蔗糖生成的葡萄糖基,转移到异麦芽糖等受体中生成低聚糖。为了提高蔬菜发酵食品中低聚糖生成量,实验从蔬菜发酵食品中筛选了低温生产高活性右旋糖酐蔗糖酶的明串珠菌,随后对分离菌株进行了鉴定及发酵特性研究。结果所筛选4个菌株均为肠膜明串珠菌,在低温下显示了很高的右旋糖酐蔗糖酶活性。这些明串珠菌菌株应用到发酵食品将会有助于提高发酵食品的感官质量和功能性。

Leuconostocs are a diversified group of heterofermantative lactic acid bacteria commonly found in the initial phase of vegetable fermented foods and they play improtant roles for produing carbon dioxide and flavor compounds. Leuconostocs are used as starter culture in the manufacture of various fermented foods. Leuxonostocs also secrete dextransucrase, which catalyzes the transfer reaction of glucose from sucrose to maltose, synthesizing mainly oligosaccharide. To increase the oligosaccharide production during food fermentation, we screened psychrotrophic Leuconostocs producing highly active dextransucrase from vegetable fermented foods, and studied their fermentation characteristics. The selected four strains were indentified as Leuconostoc mesenteroides, which can be used as function added-starters for fermented foods.